Hair relaxers are primarily used to loosen and straighten, i.e., "relax", curly, frizzy and kinky hair. Hair relaxers are typically cream products having a high pH (i.e., 12.0 to 14.0) and containing, as active components, strong alkalizing additives, such as sodium hydroxide, lithium hydroxide or calcium hydroxide, to straighten strands of hair. The action of these alkaline additive components results in swelling of the hair to permit penetration of the additives into the cortex of the hair to break chemical bonds and re-form the bonds into a new configuration, thereby relaxing the curling and/or twisting of the hair strands., If the relaxer hair product is combed through the hair during the relaxing process, less curliness and more straightening effects are obtained. Similarly, other alkaline-based hair care products, such as wave and/or curl formulations, that also re-form chemical bonds in the hair to alter the structure of the hair, are commonly used by consumers to change the appearance of the hair. A drawback related to the use of such highly alkaline products is that they can be harsh on the hair; hair may become damaged, dry, rough-feeling and difficult to comb after such relaxer products are applied.
Accordingly, needed in the art are hair compositions and products that serve to condition the hair and have the ability to provide lasting conditioning effects, without harshness, after use of the product and after shampooing. More particularly, hair relaxer compositions are also needed that both straighten and condition the hair, without causing extreme dryness and damage to the hair.
It is a goal in the art to develop hair relaxer compositions comprising one or more relaxing and conditioning components wherein the compositions cause less damage to the hair and do not make it dry and unmanageable. Also needed are hair relaxers which make hair easy to comb and contain ingredients which are stable and have long-lasting effects for the user, even after shampooing. In addition, other hair compositions and treatments, such as wave and/or curl formulations, are needed which not only perform their intended functions on the hair, but which also condition and soften the hair after use, thereby making the treated hair more manageable and causing less damage to the treated hair strands. These and other beneficial results are achieved by the present invention using cationic guars (also described and referred to synonymously heroin as cationic gum derivatives from guar or locust bean gum) to produce novel and gentle hair compositions having high alkaline pH and significant conditioning properties.
European Patent Application No. 702949 discloses cationic modified guar gum as the sole thickening agent in hair dye compositions, but does not disclose or teach cationic guars in hair relaxer compositions having alkaline pH and providing novel and lasting combing and conditioning effects.
Cationic guars are disclosed as additives in particular hair conditioner compositions for use as thickeners, but not as conditioners in line hair relaxer compositions, in Japanese Patent No. 5,345,708, U.S. Pat. No. 4,557,928 and U.S. Pat. No. 4,387,090.
As will be appreciated by those having skill in the pertinent art, commercially-available cationic guar solutions (e.g., Cosmedia; Jaguar.RTM.) are generally known to be stable in formulations that have low pH to moderately alkaline pH. In particular, Rhone-Poulenc specifies in its product literature that its quaternized hydroxypropyl guars, sold under the tradename JAGUAR.RTM., should be used in formulations having a pH in the range of 4 to 10 for optimal clarity and stability. Because the guar product literature discloses that guars are unstable at high pH, and thus lose viscosity, one skilled in the art would not be motivated, based on such product literature, to use such guar gums as additives in compositions having high pH. Accordingly, the use and formulation of cationic guars into the highly alkaline hair relaxer/conditioning compositions of the present invention is antithetical to the teachings of the art and to the knowledge of the skilled practitioner. In contrast to the teachings of the prior art, the compositions of the present invention, containing a cationic guar additive at a high pH, surprisingly afford a significant level of stability, viscosity and activity of the cationic guar oiler time.